This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-401171, filed Dec. 28, 2000, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates a silencer used in a projection type projector apparatus utilizing a light source and a light modulating element, and a projection type projector apparatus with the same.
2. Description of the Related Art
Currently, as a light source for a projection type projector, a discharge lamp of a short arc type such as a mercury lamp, a metal halide lamp or a xenon lamp is employed mainly. The discharge lamp emits light while it is being maintained in a high temperature of 1000xc2x0 C. or so, and about 90% of the energy is not converted to light to be consumed as a heat generating source. Therefore, in view of a problem of reliability of an electrode, a discharge lamp, and a reflector itself which controls and reflects light, such a configuration must be employed that a reflector having a proper space according to power is provided to perform forced air cooling, or a vent hole is provided in a reflector to perform direct forced air cooling.
A conventional projection type projector apparatus will be explained using a liquid crystal projector. The liquid crystal projector is provided with a discharge lamp which is the light source, which is provided in reflector in an approximately closed state. Furthermore, a suction port and an exhaust port are provided in the projector apparatus, the fresh air is taken in via the suction port, and the fresh air is sent to a discharge lamp by a fan, and a heated air is exhausted to outside by a exhaust fan which is provided in exhaust side. As the technique describing a liquid crystal projector having such an exhausting means, there are U.S. Pat. No. 5,993,008 publication and the like.
Since the temperature of the discharge lamp is an extremely high temperature, when the hot air is exhausted as it is, exhaust air to be exhausted or discharged outside depends on an airflow speed but will has a high temperature of 100xc2x0 C. or so. Such a high temperature is not preferable in view of safety.
Therefore, such a technique is employed that the speed of the hot air is increased until an arbitrary temperature can be achieved, or the hot air is mixed with a cooling air with a relatively low temperature which has been used to cool both polarizing elements, a liquid crystal panel and a polarizing plate which constitutes a light bulb, which are other parts to be cooled, so that exhaust air from the exhaust port is lowered to an arbitrary temperature.
In such a projection type projector apparatus, according to recent requirements for further small-sizing and higher output power, a higher power is required for the discharge lamp light source, while the apparatus set itself, namely, the reflector including the discharge lamp, both the polarizing elements and the polarizing plate constituting the light bulb, and the fan which is a cooling air suction side (exhaust side) cooler, is required for further small-sizing and weight reduction.
Considering the forced air cooling effected by the fan which is an ordinary cooling air suction air side (exhaust air side) cooling, when, for example, a light bulb is small-sized from 1.3 sun (which is a Japanese unit where 1 sun is equal to 1.3 inches) which is a representative value to 0.7 sun, light energy per unit area becomes 3.5 times or so correspondingly in order to maintain the same brightness. In such a case, air cooling effected by stronger air speed is required due to poor heat conductivities of almost all of the optical elements except for using expensive sapphire material for both polarizing elements or using an approach where it is difficult to secure reliability.
Especially, since it is assumed that a front projection type projector apparatus is used in a dark chamber environment, light leakage is not allowed from a main body thereof so that it becomes necessary to provide a complicated air passage and a narrow vent port, thereby increasing noises due to air cooling significantly. As a result, noises generated from a cooling apparatus become a problem not only in home use which is in a quiet house environment but also in ordinary business use.
That is, in the conventional projection type projector apparatus, there is a drawback that it is required to attain small-sizing, higher output and silence but it is much difficult to solve these conflicting demands collectively.
In view of the above, an attachable/detachable silencer has been made or devised, and the present invention is to provide a projection type projector apparatus whose small-sizing, higher output and silence can be achieved by mounting the silencer to the apparatus only when sound or noise reduction is required without large-sizing a main body of the projection type projector apparatus, and the silencer.
According to an aspect of the present invention, there is provided a silencer which is mounted to a projection type projector apparatus provided with optical function including a light source portion and a light bulb, and cooling means for cooling at least the light source portion by blowing cooling air to the optical function, the silencer comprising a silencer main body which takes air flowing in the cooling means or cooling air flowing out of the cooling means into silencer main body to reduce suction sound or exhaust sound of the cooling means; and mounting means for attachably/detachably mounting the silencer main body to at least one of a cooling airflow suction side and a cooling airflow exhaust side of the cooling means of the projection type projector.
According to the aspect of the present invention, the silencer is made attachable/detachable so that the silencer is mounted to the projection type projector apparatus only when sound or noise reduction is required, thereby allowing small-sizing and silence of the apparatus to be achieved simultaneously.
And, according to an aspect of the present invention, there is provided a projection type projector apparatus which irradiates light whose light amount is controlled by a light bulb in a predetermined direction is provided with a light source provided inside the projection type projector apparatus; cooling means, provided within the projection type projector apparatus, for cooling at least the light source by blowing cooling air to the light source; a silencer main body which takes cooling air flowing from the cooling means into the silencer main body once to discharge the same, thereby damping suction sound or exhaust sound of the cooling means; and mounting means which attachably/detachably mounts the silencer main body on a cooling air exhaust side of the cooling means of the projection type projector apparatus such that the mounting angle of the silencer main body can be changed continuously so that an exhaust angle of the silencer main body can be changed continuously.
According to the aspect of the present invention, the projection type projector apparatus is mounted above mentioned silencer which is mounted to the projector apparatus only when sound or noise reduction is required, thereby allowing small-sizing and silence of the apparatus to be achieved, similarly.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.